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Volume 20, Issue 3, Pages 296-306 (September 2016)
The Yersinia Virulence Factor YopM Hijacks Host Kinases to Inhibit Type III Effector- Triggered Activation of the Pyrin Inflammasome Lawton K. Chung, Yong Hwan Park, Yueting Zheng, Igor E. Brodsky, Patrick Hearing, Daniel L. Kastner, Jae Jin Chae, James B. Bliska Cell Host & Microbe Volume 20, Issue 3, Pages (September 2016) DOI: /j.chom Copyright © 2016 Elsevier Inc. Terms and Conditions
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Cell Host & Microbe 2016 20, 296-306DOI: (10.1016/j.chom.2016.07.018)
Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 1 YopM Inhibits Activation of the Pyrin Inflammasome
LPS-primed WT or knockout bone marrow-derived macrophages (BMDMs) were infected with the indicated Y. pseudotuberculosis strains for 90 min at an MOI of 30. (A and D) Caspase-1 processing in infected (A) C57BL/6, Nlrp3−/−Nlrc4−/−, or Asc−/− BMDMs and (D) C57BL/6 or Mefv−/− BMDMs was determined by western blot (WB) analysis. (B, C, E, and F) (B and E) Secreted interleukin (IL)-1β was measured by ELISA and (C and F) cell death was quantified by lactate dehydrogenase (LDH) release. Data in (B) and (C) and (E) and (F) represent average values ± SEM from three independent experiments compared to yopM mutant-infected BMDMs as analyzed by two- or one-way ANOVA, respectively. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗∗p < See also Figures S1 and S2. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 2 YopM Inhibits Pyrin to Counteract Host Protection to Yersinia
C57BL/6 or Mefv−/− mice 12–16 weeks old were infected intravenously by tail vein injection with approximately 2,000 CFU of WT Y. pseudotuberculosis or a yopM mutant. (A and B) Time to death of infected (A) C57BL/6 and (B) Mefv−/− mice was monitored for 21 days. Results are plotted to day 15 and pooled from two independent experiments with groups of four to five mice (n = 8–9). (C and D) Enumeration of bacterial burdens in the (C) spleens and (D) livers of infected C57BL/6 or Mefv−/− mice at 5 days post-infection by CFU assays. Results are pooled from two independent experiments with groups of four mice (n = 8). Results in (A) and (B) were analyzed using the log-rank test, while data in (C) and (D) were analyzed by Mann-Whitney test. ∗p < 0.05; ∗∗∗p < 0.001; ∗∗∗∗p < ; ns, not significant. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 3 The Catalytic Activities of YopE and YopT Stimulate the Pyrin Inflammasome LPS-primed BMDMs were infected with the indicated Y. pseudotuberculosis strains for 90 min at an MOI of 30. (A) Caspase-1 processing in infected lysates was determined by WB analysis. (B and C) (B) Secreted IL-1β and (C) cytotoxicity were quantified by ELISA and LDH release, respectively. (D–H) Fluorescence imaging of (D) uninfected or (E) , (F) ΔyopM-, (G) ΔyopBΔyopM-, and (H) yopER144AyopTC139AΔyopM-infected BMDMs. ASC, red; Yersinia, green; nuceli, blue. Scale bar represents 10 μm. (I) Quantification of BMDMs containing ASC foci from images in (D)–(H). Data in (B), (C), and (I) represent average values ± SEM from three independent experiments compared to yopM mutant-infected BMDMs as analyzed by one-way ANOVA. ∗p < 0.05; ∗∗∗p < 0.001; ∗∗∗∗p < See also Figure S3. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 4 The Catalytic Activities of YopE and YopT Drive Responses that Attenuate a Yersinia yopM Mutant In Vivo (A and B) C57BL/6 mice were infected intravenously via tail vein injection with ∼5,000 CFU of the indicated Y. pseudotuberculosis strains (A) or ΔyopM and (B) yopER144AyopTC139A or yopER144AyopTC139AΔyopM, and time to death was monitored for 21 days. Results are plotted to day 15 and pooled from two independent experiments with four to six mice per group (n = 8–10). Survival curves were analyzed using the log-rank test. ∗∗∗∗p < See also Figure S4. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 5 YopM Associates with Host Protein Kinases and Hijacks PRK to Negatively Regulate Pyrin by Phosphorylation (A) WB analysis was performed to detect host proteins that bound to GST or GST-YopM32777 in lysates (starting material) from HEK293T cells transfected to express Myc-tagged murine pyrin. (B) In vitro kinase assays were performed with proteins bound to GST or GST-YopM32777 in lysates of HEK293T cells that were mock (empty vector) transfected or transfected to express Myc-pyrin. Reactions performed in the presence of [γ-32P]ATP were directly loaded or immunoprecipitated using an anti-Myc antibody prior to analysis by SDS-PAGE and autoradiography. Parallel kinase reactions were performed using cold ATP and analyzed by WB analysis to verify presence of PRK2, pyrin (Myc), RSK1, and YopM. Arrowhead indicates phosphorylated Myc-pyrin. (C) LPS-primed BMDMs were infected with the indicated Y. pseudotuberculosis strains for 90 min at an MOI of 30 in the presence or absence of PRK (PKC412) or RSK (BI-D1870) inhibitors, and caspase-1 processing in infected lysates was detected by WB analysis. (D) WB analysis of IL-1β in the supernatants and lysates of Yersinia-infected, LPS-primed BMDMs that were transiently transfected with control siRNAs or siRNAs targeting PRK1 and PRK2 prior to infection. See also Figure S5. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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Figure 6 YopM Increases PRK-Mediated Pyrin Phosphorylation
Recombinant Myc-tagged N-terminal pyrin (amino acids 1–330) was incubated with either purified PRK1 or PRK2 and recombinant GST or GST-YopM32777, after which phosphorylation of pyrin was assessed by WB analysis for phosphorylated serine. Cell Host & Microbe , DOI: ( /j.chom ) Copyright © 2016 Elsevier Inc. Terms and Conditions
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